Obviously, Conrad and Johan are correct regarding the quality of an image and the overall pixel size, but having worked in PrePress for 37 years, Printers have to set a standard somewhere to recommend good print quality.
Perhaps they should word this better in their specifications (we work with multiple Printers across the world) and should say that the Effective PPI (the resolution at the final size)
should be no lower the 300.
The onus should be on the photographer, designer or repro house delivering the file to make sure this is correct, not the Printer (who should perform a Preflight regardless).
I'm sure most Printers don't need educating but have to give guidance however poorly worded that may be.
It's similar to them requesting CMYK files.
I don't work for a Printer but they don't want to take responsibility for a potentially haphazard RGB-CMYK conversion, when it's probably best for the client to see this change earlier on screen.
... View more